Combination or steam power plant

ABSTRACT

A combination or steam power plant is provided with an apparatus ( 20 ) with integrated steam condensation and water/water cooling. The apparatus ( 20 ) according to the invention is provided with a steam jacket ( 30 ) that encloses a steam space ( 31 ) with cooling pipes ( 33 ) for the steam condensation. The steam jacket ( 30 ) is provided at one outerside with one or more heat exchange chambers ( 41 ) for the water/water cooling, said heat exchange chambers being enclosed by a part ( 43 ) of the steam jacket ( 30 ) and in each case by a second, preferably semicircular cylindrical, second mantle part ( 41 ). For the steam condensation and water/water cooling, the apparatus ( 20 ) is provided with common water inlet and water outlet chambers ( 21, 24 ) for the coolant.

[0001] This application claims priority under 35 U.S.C. §§119 and/or 365to Appln. No. 100 31 789.8 filed in Germany on Jul. 4, 2000, the entirecontent of which is hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] The invention relates to a combination or steam power plant withan apparatus for condensing turbine steam and cooling water from asecondary cooling circuit.

BACKGROUND OF THE INVENTION

[0003] Steam condensers in combination or steam power plants aregenerally known. The expanded turbine steam is fed into a steam spaceenclosed by a steam jacket, where it is precipitated on cooled tubesarranged in tube bundles. The condensate generated at the tubes flowsdown into a hot well, from where it is further fed into the water/steamcircuit. In order to cool the condenser tubes, cooling water, forexample, in the case of a non-closed circuit, is removed from a naturalstream and passed through the tubes, whereupon it is returned to thestream. The cooling water is also used for other reasons in thecombination or steam power plant, for example, for recooling water orcondensate in a secondary cooling circuit with a water/water cooler. Thecooled water is then again used to cool oil for a turbo group, air orhydrogen for the generator cooling, and possibly for cooling coal mills.

[0004]FIG. 1 shows a cooling system for a steam power plant according tothe state of the art. The cooling medium is removed via a main coolingwater pump 1 and a line 2, for example, from a stream. A part of thisriver water is fed to the water inlet chambers 3 of a steam condenser 4.From there, it flows through the cooling tubes of the steam condenserto, for example, a one-flow condenser system, is collected in wateroutlet chambers 5, and is returned from there via line 6 to the stream.Instead of such a one-flow system, the steam condenser also may containa two-flow system with a deflection chamber (not shown here). Anotherpart of the river water is branched off from line 2 and is fed by meansof a second pump 7 via line 8 to one or more separate apparatuses, e.g.,one or more water/water coolers 9. After flowing through these coolers9, the river water is again fed into the return line 6. The water/watercooler 9 principally consists of a jacket enclosing a heat exchange orcooling chamber with cooling tubes, and also a water inlet chamber 10,water outlet chamber 11, and, in the case of a two-pass system, a waterreversing chamber. The cooling water and cooling circuit fluid, theclean water, flow in counter-current through the cooler, whereby thecooling water flows through the cooling tubes, and the clean water flowsaround the cooling tubes. The river water is hereby transferred in thewater inlet chamber 10 to the cooling tubes, flows from there throughthe cooling tubes, possibly also through a reversing chamber. It is thencollected again in the water outlet chamber 11, whereupon it is returnedby a line to the return line 6. The clean water or condensate to becooled is fed via lines 12 to the water/water cooler, flows on thejacket side around the cooling tubes in which the river water isflowing. There the flow path of the clean water is extended in length bymeans of deflectors and baffle plates, and leaves the cooler via linesor pipes 13. The water/water cooling usually comprises two or moreidentical apparatuses that are arranged in parallel.

[0005] The steam condenser is located in the machine hall. In a steampower plant, water/water coolers can be placed both inside and outsidethe machine building. In a combination system, however, there is notenough space for the placement of water/water coolers, which means theymust be placed outside the machine building. Additional pumps and linesare necessary for feeding the cooling water to the water/water cooler.

[0006] Even though the same coolant, for example, the river water, isused both for the steam condensation and the water/water cooling, theseknown combination and steam power plants require at least two, possiblyup to five separate apparatuses. These are constructed, manufactured andtested separately and are connected during installation with additionalpumps and lines, which cause additional costs.

SUMMARY OF THE INVENTION

[0007] Based on this state of the art, it is the objective of theinvention to design the apparatuses for steam condensation andwater/water cooling with the same coolant in a combination or steampower plant in such a way that their construction, manufacture, testingand maintenance is simplified, thus reducing their costs.

[0008] This objective is realized with a combination or steam powerplant according to claim 1, having an apparatus for steam condensationand water/water cooling for which the same coolant is used. In thecombination or steam power plant according to the invention, steamcondensation and water/water cooling are integrated in a singleapparatus. The apparatus is provided with a steam or condenser jacketthat encloses a steam space with bundles of cooling tubes for the steamcondensation. The ends of the cooling pipes are anchored in tube plates.At the outer side of the steam jacket, at least one heat exchange spaceis placed for the water/water cooling, and the heat exchange space isenclosed by a part of the steam jacket and by a second jacket part.Cooling tubes whose ends are anchored in tube plates are arranged in theheat exchange space for the water/water cooling. The apparatus is alsoprovided with at least one common water inlet chamber for the steamcondensation and water/water cooling as well as at least one commonwater outlet chamber. These are each enclosed on one side by the tubeplates for the cooling tubes for steam condensation and water/watercooling. The cooling tubes for the steam condensation pass from thecommon water inlet chamber through the steam space. The cooling tubesfor the water/water cooling pass through the heat exchange room for thewater/water cooling to the common water outlet chamber.

[0009] A coolant, for example, river water, is fed via a line into thecommon water inlet chamber and flows from there through the coolingtubes of the steam space and at the same time through the cooling tubesof the heat exchange space for the water/water cooling. After flowingthrough the cooling tubes, it is again collected in the common wateroutlet chamber and fed from there into a return line.

[0010] In a first preferred embodiment, the second jacket part of theheat exchange space for the water/water cooling is constructed in theshape of a semicircular cylinder. In view of the pressure differentialbetween the steam space, in which a vacuum is present, and the heatexchange chamber, where a pressure of, for example, 5 bar, is present,this shape is the best suited. Tube support plates that are arranged inthe heat exchange chamber for the water/water cooling contribute to thesupport and reinforcement of the condenser steam jacket, and serve asbaffle plates that lengthen the flow path of the clean water flowing onthe jacket side. They also reinforce the jacket of the heat exchangespace for the water/water cooling.

[0011] In further embodiments, the second jacket part of the heatexchange chamber for the water/water cooling has a cylindrical shape,yet not semicircular cylindrical shape, or it has a block shape in themanner of a box with corresponding supports, or an adequate jacketthickness in order to reinforce the jacket walls.

[0012] In a further embodiment of the invention, the common water inletchamber and water outlet chamber for the coolant for the steamcondensation and for the water/water cooling are each divided into twoparts. The cooling water flows from the first part of the water inletchamber through the tubes in the first heat exchange chamber for thewater/water cooling, and through a part of the tubes for the steamcondensation. It is then collected in the first part of the water outletchamber. From the second part of the water inlet chamber, the coolingwater flows through the tubes of the second heat exchange chamber forthe water/water cooling, and through another part of the tubes for steamcondensation. It is then collected in the second part of the wateroutlet chamber. This permits an interruption of the coolant flow throughone half of the condenser tubes and one of the two water/water coolersduring maintenance work or an interruption of the operation of part ofthe integrated apparatus.

[0013] The integrated apparatus according to the invention is provided,for example, with two heat exchange chambers for water/water cooling aswell as two common water inlet and water outlet chambers. Here thecooling water for the first heat exchange chamber and a first part ofthe steam condenser is collected in the first water inlet and wateroutlet chamber. The cooling water for the second heat exchange chamberand a second part of the steam condenser is collected in the secondwater inlet and water outlet chamber. The first part of the steamcondenser consists, for example, of two tube bundles, and the secondpart of two more tube bundles.

[0014] In a further embodiment of the invention, the integratedapparatus for steam condensation and water/water cooling is designed asa two-pass system and is provided for this purpose with at least onecommon reversing chamber for the cooling water for steam condensationand water/water cooling.

[0015] Another apparatus according to the invention is identical to theinitially described apparatus in that it has common water inlet chambersand heat exchange chambers for the water/water cooling that areinstalled at the outer side of the steam jacket. However, instead of thecommon water outlet chambers, it has separate water outlet chambers forthe cooling water for the steam condensation and for the cooling waterfor the water/water cooling, as well as one or more water reversingchambers. These are used to redirect the cooling water for the steamcondensation or the cooling water for the water/water cooling. Thisapparatus comprises for the steam condensation a single-pass system forthe cooling water, and for the water/water cooling a double- or two-passsystem for the cooling water. Alternatively, the apparatus comprises forthe water/water cooling a one-flow system for the cooling water, and forthe steam condensation a two-pass system for the cooling water.

[0016] The apparatus according to the invention primarily has theadvantage that the installation of the heat exchange chamber for thewater/water cooling and the common water chambers of the integratedapparatus eliminate the cooling water system for a separately placedwater/water cooler, and the coolant is fed simultaneously to the coolingtubes for the steam condensation and for the water/water cooling byusing only the main cooling water pump, and without additional lines andsecondary pumps. This greatly reduces the space requirement for thewater/water cooling and permits placement of the water/water coolinginside the machine hall in the case of combination or steam powerplants, or it permits space savings in the case of steam power plants.Instead of two or more apparatus, now only a single apparatus isrequired, which results in reduced costs for construction, manufacture,and installation as well as for testing, operational safety, andmaintenance. Finally, the integrated apparatus according to theinvention requires only a single tube cleaning system that is able toservice both the tubes for the steam condensation as well as those forthe water/water cooling.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Preferred embodiments of the invention are described below withreference to the accompanying drawings, wherein:

[0018]FIG. 1 illustrates a schematic view of a part of a steam powerplant according to the state of the art, with a steam condenser and aseparate water/water cooler with corresponding cooling water systems,

[0019]FIG. 2 illustrates a schematic view of a part of a steam powerplant according to the invention, with an integrated apparatus for thesteam condensation and water/water cooling,

[0020]FIG. 3 illustrates a vertical cross-sectional view of anintegrated apparatus for the steam condensation and water/water coolingaccording to the invention,

[0021]FIG. 4 illustrates a horizontal cross-sectional view of anintegrated apparatus for the steam condensation and water/water coolingaccording to the invention, and

[0022]FIG. 5 illustrates a vertical cross-sectional view of a heatexchange chamber for the water/water cooling in detail, according to theinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0023]FIG. 1 has been described initially as the state of the art.

[0024] The schematic in FIG. 2 shows the integrated apparatus accordingto the invention for the steam condensation and water/water cooling. Byusing a primary cooling water pump 1, river water or cooling water fromanother source, for example from a cooling tower, is fed via the line 2to the integrated apparatus 20. The cooling water is collected first intwo common water inlet chambers 21 for the steam condensation andwater/water cooling, where it is also distributed to the cooling tubesin the steam space for the steam condensation and to the cooling tubesof one of the two heat exchange chambers 23 for the water/water cooling.After flowing through these cooling tubes, it reaches the common wateroutlet chambers 24, in which it is again collected and which it leavesvia pipes or lines. These pipes or lines finally lead back to the returnline 6 that returns the cooling water back to the river or coolingtower.

[0025] Lines 25 and 26 are part of a secondary cooling circuit for wateror condensate. The former lead to the apparatus 20, through which thewater or condensate to be cooled reaches the heat exchange chambers 23.There, it is cooled during a heat exchange with the cooling tubes andleaves the heat exchange chambers 23 via lines 26. Because of lines 25and 26, the two heat exchange chambers 23 can be arranged parallel.

[0026] The schematic shows common water inlet chambers 21 and commonwater outlet chambers 24 for the steam condensation and water/watercooling. One water inlet chamber 21 and one water outlet chamber 24 areprovided, for example, for the cooling tubes of the top tube bundle inthe steam space and the top heat exchange chamber for the water/watercooling. The second water inlet chamber and water outlet chamber isprovided for the cooling tubes in the lower bundle of tubes in the steamspace and the lower heat exchange chamber for the water/water cooling.This division makes it possible to eliminate part of the integratedapparatus for the purposes of partial loads, inspection, tube cleaning,or maintenance. The schematic furthermore shows the common jacket wallsfor the steam space and the heat exchange chamber for the water/watercooling. By integrating the steam condensation and water/water coolinginto a single apparatus, the cooling water inflow and tube cleaningsystem for the water/water cooling is eliminated.

[0027]FIG. 3 and FIG. 4 show a preferred embodiment of the integratedapparatus 20 according to the invention. FIG. 3 shows the arrangementand preferred, semicircular cylindrical shape of the heat exchangechambers for the water/water cooling that are connected with the steamjacket for the steam condensation. A steam jacket 30 encloses a steamspace 31 for the steam condensation with several horizontally orsuperimposed tube bundles 32. Steam flows from the turbine into thesteam space, where it is precipitated on cooling tubes 33 through whichthe cooling water flows. The resulting condensate is collected in thehot well 34. Two heat exchange chambers 41 for the water/water coolingare provided on an outer side of the steam jacket 30. Each heat exchangechamber 41 is enclosed by a part 43 of the steam jacket 30 as well asthe semicircular cylindrical second mantle part 40 that is welded to thesteam jacket 30. In view of the pressure differential between the steamspace 31 and the heat exchange chamber 41 of, for example, 5 bar, thesemicircular cylindrical shape of the second jacket part 40 is suitedbest. Other shapes for the second jacket part 40, for example, roundedshapes or box shapes with correspondingly reinforced walls, also couldbe realized. The heat exchange chambers are provided with cooling tubes42 that extend parallel to the cooling tubes 33 in the steam space 31,and through which the same cooling water flows. An inlet pipe 44 and anoutlet pipe 45 are provided on the second jacket part 40. Clean water orcondensate flows through the inlet pipe 44 into the heat exchangechamber 41 and there flows around the cooling tubes 42 and leaves theheat exchange chamber 41 through the outlet pipe 45. The shownapparatus, for example, has two common water inlet chambers and twocommon water outlet chambers, whereby the first inlet and outletchambers are intended for the top heat exchange chamber and the two toptube bundles in the steam space, and the second inlet and outletchambers for the lower heat exchange chamber and the two lower tubebundles.

[0028]FIG. 4 shows the arrangement of the common water chambers for thewater/water cooling and the steam condensation. The common water inletchamber 21 is provided on a first side of the apparatus 20. River wateror another cooling water is fed via inlet pipes 27 into the water inletchamber 21 and collected there. It then flows into cooling tubes 33 and42 for the steam condensation or water/water cooling, whereby saidcooling tubes are anchored in tube plates 29. At the opposite side ofthe apparatus 20, a common water outlet chamber 24 is arranged, intowhich the cooling water flows and in which it is collected. It thenflows via outlet pipe 27′ to the return line.

[0029] In a variation, the water inlet and water outlet chambers may bedivided with a horizontal dividing wall (not shown here) or may consistof two individual water inlet or water outlet chambers. The coolingwater from the water chamber parts or individual water chambers flowsthrough the integrated apparatus 20, as shown in FIG. 2.

[0030] In the heat exchange chamber 41 for the water/water cooling, thewater to be cooled flows around the cooling tubes 42 and tube supportplates 48, 48′, which additionally support the steam jacket 30, 43 andsemicircular cylindrical jacket 40. As shown in FIGS. 4 and 5, its flowpath leads around several support plates that simultaneously function asbaffle plates or deflectors 48, 48′, thus lengthening the cooling flowpath. The deflectors 48 each are welded to the steam jacket part 43 andpart of the semicircular cylindrical second jacket part 40, while thedeflectors 48′ are welded to a large part of the semicircularcylindrical jacket 40. The invention can be used for combination andsteam power plants whose steam condenser lies under the turbine, and inwhich the turbine steam flows off vertically towards the steamcondenser. It can also be used for installations whose steam condenseris placed at equal level in relation to the steam turbine, and in whichthe turbine steam flows off horizontally into the steam condenser.

What is claimed is:
 1. Combination or steam power plant with a steamcondensation and water/water cooling characterized in that the steamcondensation and water/water cooling are integrated in a singleapparatus (20) comprising a steam jacket (30) that encloses a steamspace (31) with bundles (32) of tubes (33) for the steam condensation,and that is provided at the outer side of the steam jacket (30) with oneor more heat exchange chambers for the water/water cooling, where theone or more heat exchange chamber(s) is/are surrounded by a part (43) ofthe steam jacket (30) and a second jacket part (40), in that the secondjacket part (40) of the one or more heat exchange chamber(s) (41) isconnected to the outer side of the steam jacket (30), and cooling tubes(42) for the water/water cooling are provided in the one or more heatexchange chamber(s) (41), and the integrated apparatus (20) for thesteam condensation and water/water cooling is provided with one or morecommon water inlet chambers (21) and one or more common water outletchambers (24) for a coolant that is intended for the steam condensationand the water/water cooling, and the cooling tubes (33) in the steamspace and the cooling tubes in the heat exchange chamber for thewater/water cooling each are connected via tube plates (29) with thecommon water inlet chamber (21) and the common water outlet chamber(24).
 2. Combination or steam power plant as claimed in claim 1,characterized in that the second jacket part (40) of the one heatexchange chamber (41) or of the several heat exchange chambers (41) isconstructed cylindrically.
 3. Combination or steam power plant asclaimed in claim 1, characterized in that the second jacket part (40) ofthe heat exchange chamber or of the several heat exchange chambers (41)is constructed in box or block shape.
 4. Combination or steam powerplant as claimed in claim 1, characterized in that the integratedapparatus (20) for the steam condensation and water/water cooling is atwo-pass apparatus and is provided with one or more common reversingchamber(s) for the coolant.
 5. Combination or steam power plant with asteam condensation and water/water cooling, characterized in that thesteam condensation and water/water cooling are integrated in a singleapparatus (20) comprising a steam jacket (30) that encloses a steamspace (31) with bundles (32) of tubes (33) for the steam condensation,and that comprises at the outer side of the steam jacket (30) with oneor more heat exchange chambers for the water/water cooling, where theone or more heat exchange chamber(s) is/are surrounded by a part (43) ofthe steam jacket (30) and a second jacket part (40), in that the secondjacket part (40) of the one or more heat exchange chamber(s) (41) isconnected with the outside of the steam jacket (30), and cooling tubes(42) for the water/water cooling are provided in the one or more heatexchange chamber(s) (41), and the integrated apparatus (20) for thesteam condensation and water/water cooling is comprises one or morecommon water inlet chambers (21) and one or more common reversingchambers for a coolant that is intended for the steam condensation andwater/water cooling, and has separate water outlet chambers for thesteam condensation and water/water cooling, and the cooling tubes (33)in the steam space and the cooling tubes in the heat exchange chamberfor the water/water cooling each are connected via tube plates (29) withthe common water inlet chamber (21), each are connected with the commonwater reversing chamber (24), and each are connected with the separatewater outlet chambers.